Has the Pendulum Reached its Apex?

By Matt RiesPosted June 12, 2014

Thanks to the work of epidemiologist John Snow in 1854, we learned that the growing density of cities and their inhabitants’ needs for clean water and waste disposal could no longer rely on inadequate, localized water supply and disposal of used water. Thus began a long journey that vastly improved the lives of millions of urban dwellers. Our infrastructure evolved from local sources of unprotected water, to centralized treatment systems, and distribution throughout the cities. Eventually, centralized wastewater treatment was added, and this system has served us well.In a world of seemingly unlimited resources, the materials and energy required for a vast, urban centralized water system were not a consideration, but we now know our resources are limited and increasingly stressed. The energy used to extract, treat, distribute and clean our water is limited. The materials used to build the infrastructure are limited. The water itself is limited. So then we must ask: Is there a more sustainable way to approach our urban water infrastructure without sacrificing the immense public health benefits of centralized infrastructure?

The pendulum has swung a long way toward centralized systems, but there is a sense it is slowly starting to swing back. Water infrastructure in the imaginable future will still have centralized elements. We are locked in to our existing systems at least in the near future, but we’re starting to see some chipping away at that paradigm, with more distributed elements integrated into the mix and a growing conversation and body of research on the topic.

With respect to urban stormwater management, decentralization is well underway. However, it is rarely referred to as “decentralized.” Interest in low-impact development (LID) is spurring LID competitions across the nation, and the U.S. EPA is explicitly encouraging the use of green infrastructure to help alleviate sewer overflows. These approaches are, in effect, the decentralization of urban stormwater management.

It’s a different story for urban drinking water and wastewater. Due to concerns over potable water quality or the public acceptance of wastewater recycling, progress has been slow. Regulatory and institutional barriers remain. Nonetheless, a small number of urban utilities are moving forward. The first sewer-heat recovery system in North America was built in Vancouver on a district scale for the 2010 Olympics. Several other cities are now trying this method of decentralized energy recovery. New technologies now allow wastewater to be treated to high quality onsite and recycled at the point of use, offsetting potable water usage.

These changes are also happening overseas. An energy self-sufficient “water machine” generating fit-for-purpose water is being built in China, where colleges in dense, urban areas are recycling water onsite. Decentralized systems are integrating water, waste and energy in Sweden. Sewer mining in Australia is addressing severe water scarcity. Yet in many of these examples, along with those in the U.S., a private entity or developer is frequently driving the change.

Will U.S. utilities see this shift as an opportunity or a threat? It took over a century for the pendulum to reach its apex. Will the new direction and momentum creep along, or pick up the pace? No one knows, and market drivers, including commodity prices, consumer demands and climate change, will impact the transition. Innovators are charting a new path, and only time will tell how urban water utilities react to this changing paradigm.

Has the Pendulum Reached its Apex?

By Matt RiesPosted June 12, 2014

Thanks to the work of epidemiologist John Snow in 1854, we learned that the growing density of cities and their inhabitants’ needs for clean water and waste disposal could no longer rely on inadequate, localized water supply and disposal of used water. Thus began a long journey that vastly improved the lives of millions of urban dwellers. Our infrastructure evolved from local sources of unprotected water, to centralized treatment systems, and distribution throughout the cities. Eventually, centralized wastewater treatment was added, and this system has served us well.In a world of seemingly unlimited resources, the materials and energy required for a vast, urban centralized water system were not a consideration, but we now know our resources are limited and increasingly stressed. The energy used to extract, treat, distribute and clean our water is limited. The materials used to build the infrastructure are limited. The water itself is limited. So then we must ask: Is there a more sustainable way to approach our urban water infrastructure without sacrificing the immense public health benefits of centralized infrastructure?

The pendulum has swung a long way toward centralized systems, but there is a sense it is slowly starting to swing back. Water infrastructure in the imaginable future will still have centralized elements. We are locked in to our existing systems at least in the near future, but we’re starting to see some chipping away at that paradigm, with more distributed elements integrated into the mix and a growing conversation and body of research on the topic.

With respect to urban stormwater management, decentralization is well underway. However, it is rarely referred to as “decentralized.” Interest in low-impact development (LID) is spurring LID competitions across the nation, and the U.S. EPA is explicitly encouraging the use of green infrastructure to help alleviate sewer overflows. These approaches are, in effect, the decentralization of urban stormwater management.

It’s a different story for urban drinking water and wastewater. Due to concerns over potable water quality or the public acceptance of wastewater recycling, progress has been slow. Regulatory and institutional barriers remain. Nonetheless, a small number of urban utilities are moving forward. The first sewer-heat recovery system in North America was built in Vancouver on a district scale for the 2010 Olympics. Several other cities are now trying this method of decentralized energy recovery. New technologies now allow wastewater to be treated to high quality onsite and recycled at the point of use, offsetting potable water usage.

These changes are also happening overseas. An energy self-sufficient “water machine” generating fit-for-purpose water is being built in China, where colleges in dense, urban areas are recycling water onsite. Decentralized systems are integrating water, waste and energy in Sweden. Sewer mining in Australia is addressing severe water scarcity. Yet in many of these examples, along with those in the U.S., a private entity or developer is frequently driving the change.

Will U.S. utilities see this shift as an opportunity or a threat? It took over a century for the pendulum to reach its apex. Will the new direction and momentum creep along, or pick up the pace? No one knows, and market drivers, including commodity prices, consumer demands and climate change, will impact the transition. Innovators are charting a new path, and only time will tell how urban water utilities react to this changing paradigm.

Matthew Ries, P.E., is Chief Technical Officer for WEF. In this capacity he oversees staff with responsibility for the technical programming and development of WEF’s e-Learning program, webcasts, seminars, specialty conferences, and WEFTEC, the world’s largest annual water conference. In addition, these staff serve as liaisons to over 20 technical committees and communities of practice. He serves as the staff liaison to the Utility Management Committee and directs WEF’s initiatives on innovation and nutrients.